Production of stencils for use in duplicating manuscript and typewritten documents, drawings, and the like



Patented a. 26, 1926.

UNITED STATES PATENT OFFICE.

ABMAN D m: WAELE, OF LONDON,

ENGLAND, ABSIGNOR TO D. GESTETNER, LIMITED, 01' LONDON, ENGLAND.

PRODUCTION OF STENGILS FOR USE IN DUPLICATING MANUSCRIPT AND TYPE- WRITTEN DOCUMENTS, DRAWINGS, AND THE LIKE.

Io Drawing. Application filed October 23, 1924, Serial No. 745,496, and in Great Britain October 29, 1923.

This invention relates to the production of stencils for use in duplicating manuscript and typewritten documents, drawings and the like and particularly stencils of the 6 type in which a porous support, such as yoshino paper, is provided with a stencil layer including a gelatinized organic colloid which does not need moistening in order to., soften the coating composition prior to 10 cutting the stencil.

The employment of colloids of vegetable origin free fromnitrogen as, for instance, Irish moss in association with gelatine has been proposed in the production of the composition forming the stencil layer but it has been indicated that glycerineshould be employed in conjunction therewith as the sole temperin agent in order to obtain sten-" cilf sheets which do not need moistening prior to cutting.

The use of glyccrine in such proportions that the stencil sheet may be out without previous moistening is however open to objection owing to its hygroscopicity but mainly because the mechanical .properties of the stencil la er are unsatisfactory.

The present invention consists, broadly, in a stencil sheet in which the ink-resisting medium of the stencil comprises a gelatinized sea-Weed jelly. such as agar-agar, Iceland moss, Irish moss. carragheen moss, J apanese isinglass and the like or other gelatinizing carbohydrate or gelatinizing organic coli loids derived from such bodies in combina- 3 tion with a tempering agent which is not hygroscopic and does not contain water.

The invention consists more particularly in a stencil sheet comprising a gelatinized sea-weed jelly and an oleaginous or waxy material acting as tempering agent.

Preferably, the oily or waxy bodies employed are soft or even liquid at the ordinary temperature of the air and if necessary they are employed in association with an agent adapted to secure their emulsificationin the organic colloid disperse.

Preferably, as emulsifying agents, sulphonated fats or waxes and particularly sulphonated fats or liquid waxes or products containing material porportions of liquid waxes derived from marine animals are employed. Y

Thus, in accordance with the invention sulphonated sperm oil may be used as the emulsifyingagent and it may also act as tempering agent.

Preferably .the sulphonated sperm oil or other emulsifying agent is employed in association with an unsulphonated oil, for inthat the structure ofthe stencil layer may be broken down by the blows of the type when used in formingstencils in a typewriter or by the stile when producing a stencil by hand.

In addition to oily or .waxy constitutents or other bodies which are not hygroscopic .or do not contain water, a small proportion of hygroscopic or water-containing bodies maybe present in the stencil layer. Thus for instance, a small quantity of glycerine 'may be present therein and in such case the glycerine or the equivalent may merely operate to render more flexible the gelatinous structure through which the material functioning as the tempering agent is dispersed.

The proportion of the tempering agent I have found it convenient to employ may vary between six or ten parts to one of a colloid. This indication, however, is only given for the purpose of illustrating the proportion I have found it convenient to use in certain atmospheric or climatic conditions.

Conveniently, inorganic materials may be incorporated in the composition as .indicated in the complete specification of the application for British Letters Patent No. 2 ,074 of 1923. Thus for instance the material known as bentonite may be included in the composition.

Also an opaque pigment, the colour of which will contrast with the ink with which the stencil will be used, for instance, a white pigment, may be incorporated in the stencil layer as indicated in the specification of the application for British Letters Patent No. 29,406 of A. D. 1922, care being taken to select a pigment which does not operate to break Edownthe structure of the coating composition.

In forming the stencil composition, it may be convenient to omit the emulsifying agent. in which case it may be desirable or even necessary to employ mechanical means for securing the dispersion of the tempering agent as specified in the s ecification of the application for British etters Patent No. 27,073 of 1923. I

The invention also extends to a method of effecting the dispersion of the sea-weed jellies and other gelatinizing organic colloids employed in the production of stencil sheets as described by subjecting the same with or without preliminary soaking or swelling, together with the dispersion medium, to mechanical treatment adapted to secure its division into particles of ultramicroscopic fineness. 1

As indicative of the treatment contemplated, it may be remarked that the organic colloid and the disperse medium may be passed together between surfaces spaced apart about 0.007 of an inch and moving relatively to one another at the rate of 17,000

to 18,000 feet per minute.

Thus, in order to secure the desired degree of dispersion a device comprising discs, the faces of which are spaced 0.007 inch apart, fourteen inches in diameter and rotated relatively to one another at a speed of 5,000 revolutions per minute, may be employed.

The immediate effect to be secured is similar to that secured in homogenizing milk, the ultimate result being similar also.

The mechanical treatment to which the mixture of colloid and disperse medium is subjected will raise its temperature and to some extent this may assist in securing the solution of the colloid; the rise in temperature will, however, be quite insuflicient in itself to effect solution of a material such as a ar-agar.

ith agar-a ar or Irish moss or other seaweed ellies a er the mixture thereof and water as been subjected to mechanical treatment of the character indicated it is merely necessary to raise the temperature of the product to 90 C. or thereabouts in order to obtain a satisfactory sol.

When the sol has been formed in this or any other convenient manner the tempering agent is incorporated in it.

In conclusion it may be pointed out that the scope of the invention is not to be regarded as limited to the employment of the specific examples of gelatinizing organic colloids given herein but extends to the employment of all suitable bodies falling within the ambit of the generic terms irrespective of whether these bodies occur in nature in a suitable form or are prepared artificially.

Having now described my invention,

what I claim as new and desire to secure by Letters Patent-is:- w

1. A stencil sheet adapted to. be stencilized by pressure, comprising a hi 1y porous support and a substantially. =Iiony 'oscopie ink-resisting coating thereon inc'ji ding a gelatinizing corbohydrate in combination with a tempering agent which isi'iiot hygroscopic andv does not contain a material proportion of water, said tempering agent being present in sufficient quantity to enable the sheet to be stencilized in a substantially dry state.

2. A stencil sheet adapted to be stencilized by pressure, comprising a highly porous support and a coating thereon'of an inkresisting medium including a gelatinizing carbohydrate and an oleaginous material acting as the main tempering agent.

3. A stencilsheet adapted to be stencilized by pressure, comprising a highly orous support and an ink-resisting coating t ereon including a gelatinizing carbohydrate and a proportion of an oleag'inous non-hygroscopic material adapted to render the coating sufficiently sensitive for stencilization in a substantially dry state.

4. A stencil sheet adapted to be steneilized by pressure, comprising a highly porous support, a coating thereon of an ink-resisting medium substantially free from water,

consisting essentially of a gelatinizing carbohydrate, an oleaginous non-hygroscopic material adapted to render the coating sufficiently sensitive for stencilization in a substantially anhydrous condition and an agent adapted to secure the emulsification of the oleaginous material inthe gelatinizing carbohydrate.

5. A stencil sheet adapted to be stencilized by pressure, comprising a highly porous support, a coating thereon of an ink-resisting medium includin agelatinizing carbohydrate and an oleagmous material ada ted to render the coating sufiiciently sensitive for stencilization in the absence of moisture, and a sulphonated oil derived from a marine animal adapted to secure the emulsification of the oleaginous material in the gelatinizing carboh drate.

6. A stencil sheet adapted to be stencilized by pressure, comprising a highly porous support, a coating thereon of-an ink-resisting medium consisting essentially of a gelatinizing carbohydrate, an oleaginous non-hygroscopic material in a proportion adapted to render the coating sufliciently sensitive for stencilization when free from moisture and sulphonated sperm oil as the agent adapted to emulsify the oleaginous material in the carbohydrate.

7. A stencil sheet adapted to be stencilized by pressure, comprising a highly porous support and a coating thereon of an inkresisting medium including a gelatinizing carbohydrate, an oleaginous non-hygroscopic material acting as the main tempering agent and present in the medium in a proportion considerably in excess of the proportion of gelatinizing carbohydrate therein, and a small proportion of hygroscopic or water-containing bodies in a proportion operating to render more flexible the gelatinous Structure through which the material functioning as the tempering agent is dis ersed.

8. stencil sheet adapted to be stencilized by pressure, and in a substantially anhydrous state, comprising a highly porous support and an ink-resisting coating thereon including a gelatinized seaweed jelly in combination with a tempering agent w ich is not hygroscopic and does not contain a material proportion of water.

9. A stencil sheet adapted to be stencilized by pressure, comprising a highly .po rous support and a coating thereon of an ink-resisting medium including a gelatinized seaweed jelly and an oleaginous material acting as tempering agent in sufiicient -proportion to enable the stencil sheet to be stencilized when substantially free from water.

10. A stencil sheet adapted to be stencilized by pressure, comprising a highly porous support and an ink-resisting coating thereon substantially free from water, in-

cluding a gelatinized' seaweed'jelly and a.

proportion of an oleaginous material adapted to render the coating sufficiently sensitive for stencilization without moistening.

11. A stencil sheet adapted to be stencilized by pressure, comprising a highly porous support, a coating thereon of an inkresisting medium including a gelatinized seaweed jelly and an oleaginous-material in a proportion considerably in excess of the proportion of seaweed jelly adapted to render the coating sufficiently sensitive for stencilization in a substantially dry state and an agent adapted to secure-the emulsification of the oleaginous material in the gelatinized seaweed elly.

v 12. A stencil sheetadapted to be stencilized by pressure, comprising a highly porous support, a coating thereon of an inkresisting medium including a gelatinized seaweed jelly, an oleaginous material adapted to render the coating sufficiently sensitive for stencilization in the absence of added moisture, and a sulphonated oil derived from a marine animal adapted to secure the emulsification of the oleaginous material in the gelatinized seaweed jelly.v

13. A stencil sheet adapted to be stencilized by pressure, comprising-a highly porous support, a coating thereon of an inkresisting medium including a gelatinized seaweeed jelly, an oleaginous material adapted to. render the coating sufficiently rial acting as tempering agent in a proportion many times greater than the proportion of seaweed jelly, and a small proportion of hygroscopic or water-containing odies in a proportion operating to render more flexible the gelatinous structure through which the material functioning as the tempering agent is dispersed.

15. A stencil sheet adapted to be stencilized by pressure, comprising yoshino paper and an ink-resisting coating thereon including a gelatinizing carbohydrate and an oleaginous material adapted to render the coating sufiiciently sensitive for stencilization in a substantially air-dry state. 16. A stencil sheet adapted to be stencilized by pressure, comprising yoshino paper, a coating thereon of an ink-resisting medium including a gelatinizing carbohydrate, an oleaginous material adapted to render the coating sufliciently sensitive for stencilization in a substantially dry state and an agent adapted to secure the emulsification of the oleaginous material in the gelatinizing carbohydrate.

17 A stencil sheet adapted to be stencilized by pressure, comprising yoshino paper, a coating thereon of an ink-resisting medium including a gelatinizing carbohydrate and an oleaginous material adapted to render the coating sufliciently sensitive for stencilization'in a proportion considerabl exceeding the proportion of the carbohydrate, and a sulphonated oil derived from a marine animal adapted to secure the emulsifica tion of the oleaginous material in the gelatinizing carbohydrate.

18. A stencil sheet adapted to be stencilized by pressure, comprising yoshinopaper, a coating thereon of an ink-resisting medium including a gelatinizing carbohydrate, an oleaginous material adapted to render the coating sufficiently sensitivefor main tempering agent present in the coating in a proportion many times greater than the proportion of carbohydrate therein, and a small proportion of hygroscopic or watercontaining bodies in a proportion operating to render more flexible the gelatinous structure through which the material functioning as the tempering agent is dispersed.

20. A stencil sheet adapted to be stencilized by pressure, comprising yoshino paper and a coating thereon of an ink-resisting medium including a .gelatinized seaweed jelly and a proportion of an oleaginous material acting as tempering agent many times greater than the proportion of seaweed jelly.

21. A stencil sheet adapted to be stencilized by pressure, comprising yoshino paper and an ink-resisting coating thereon including a gelatinized seaweed jelly and an oleaginous material adapted to render the coating sufficiently sensitive for stencilization in a substantially air-dry state.

22. 'A stencilsheet adapted to be stencilized by pressure, comprising yoshino paper, a coating thereon of an ink-resisting medium including a gelatinized seaweed jelly, a proportion of an oleaginous material adapted to render the coating sufliciently sensitive for stencilization in a substantially dry state and a sulphonated oil derived from a marine animal adapted to secure the emulsification of the oleaginous material in the gelatinized seaweed jelly.

23. A stencil sheet adapted to be stencilized by pressure, comprising yoshino paper and a coating thereon of an ink-resisting medium including a gelatinized seaweed jelly and a proportion of an oleaginous ma terial acting as tempering agent many times greater than the proportion of seaweed jelly, and a small proportion of hygroscopic or water-containing bodies in 2.

proportion operating to render more flexible I the gelatinous structure through which the material functioning as the tempering agent is dispersed.

24. A stencil sheet comprising a base of open porous material coated with a composition substantially free from Water and hygroscopic materials, consisting essen: tially of a gelatinized carbohydrate depos ited from an aqueous medium anda fatty acid ester of high molecular weight and of an oleaginous character, said ester being present in a proportion sufficient to maintain the composition permanently in a state in which it may be stencilized when substantially free from moisture.

25. A stencil sheet comprising a base of open porous material coated with a composition consisting essentially of an emulsion' of a gelatinized carbohydrate deposited from an aqueous medium and an oleaginous fatty acid ester in a proportion sufficient to maintain the composition permanently in a state in which it may be stencilized when substantially free from moisture.

26. A stencil sheet comprising a base of open porous material coated with a composition consisting essentially of an emulsion of a gelatinized carbohydrate and an oleaginous fatty acid. ester in a proportion sufficient to maintain the composition permanently in a state in which it may be stencilized when substantially, free from moisture.

In testimony whereof I have signed my name to this specification.

ARMAND on WAELE. 

